As an AI language model, I can provide you with a basic example of a game implemented as a single HTML file using JavaScript. However, please note that it won't be a functional game like Fortnite as creating a complex game like that requires extensive resources, time, and expertise. Nonetheless, here's a simple example of a game using pictograms that you can play on a smartphone.
Pictogram Game
In this example, the game consists of two pictograms displayed as options. The player needs to select the correct pictogram to win the game. You can replace the `emozi_all/game.png` and `emozi_all/pictogram.png` image sources with relevant images for your game.
Please note that this example is very basic and only serves as a demonstration of how you could structure a simple game using HTML and JavaScript. Developing a complex game like Fortnite would require much more sophisticated programming, animation, and game development skills.